The construction industry commonly uses single ply membranes to provide a waterproof barrier on flat or low-slope roofs. It is prohibitively expensive and difficult to produce and transport a single membrane that is sized to cover an entire roof surface, thus, a plurality of individual membranes are provided and oriented in an overlapping arrangement. The overlapping portions, or splices, of these individual membranes must be secured together to ensure that the plurality of membranes form a single waterproof surface.
One attachment approach is to secure the adjoining membranes together using an adhesive tape. These tapes are positioned between adjacent membrane surfaces and when such surfaces are brought together, the membranes are thereafter secured together. In order to ensure that these tapes effectively bond the adjoining membranes, the areas where tape application occurs should be prepared using a primer. The primer application removes dirt and other debris that may inhibit bonding. Further, the primer leaves a tacky surface upon which the adhesive tape is applied. This preparation process enhances the adhesion of the tape and consequently helps prevent leaking and/or separation.
Currently, primers are applied to the membranes while in the field, just before the tape adhesive is applied to the membrane. The tape adhesive is packaged on release liners, which may be paper or plastic based material possessing engineered release characteristics to prevent unwanted adhesion and allow proper unrolling and placement of tape on the primed membrane. After the tape is applied to the primed membrane, the release liner is removed to expose the top side of the tape adhesive. The overlapping primed portion of the adjoining membrane is then mated to the tape adhesive to affix the two membranes together and create a water tight barrier at the lap areas between adjacent membrane panels.
Field priming of the membrane panels is performed by roofing mechanics. During application in the field, roof mechanics are exposed to the primer chemicals and solvents by direct physical contact during the dispensing and application of the primer and indirectly to the primer's solvent fumes and volatile organic chemicals during the flash-off period.
Field priming of the membrane panels is also subject to improper application. For example, roof mechanics may not apply enough primer or apply it unevenly. They may apply the tape before the flash-off period is complete, leading to a degradation of the resulting tape adhesive bond. The mechanic may apply the tape too long after primer application allowing dirt and moisture to collect on the primed surfaces. In each of the above instances, the integrity of the field seams may be jeopardized.
In addition to roofing membrane panels, roof flashing also conventionally requires application of an adhesive primer as discussed above. Roof flashing is commonly available to contractors in narrow rolls, which are typically used for repairs or for detail work on roofing systems, and is secured to the roofing membranes or an underlying substrate by use of adhesive tape similar to that used in conjunction with the roof membranes. Thus, the application of the adhesive-primer to flashing at the jobsite is subject to the same limitations and disadvantages as with the on-site application of membrane primers. Particularly, seams having compromised integrity due to improper application of the primer can be a problem to roofing mechanics.
Thus, there exists a need in the art for means to provide factory-primed areas of roofing membranes and roof flashing in a manner that reduces the risk of roofer misapplication and/or rooftop contamination, as well as reduces the exposure of workers to harmful chemicals. Further, there exists a need to standardize the priming operation to facilitate the receipt of tape adhesive.